Fluid sampling process and apparatuses therefor

ABSTRACT

Processes and apparatuses for automatically sampling gases and/or liquids by the steps of (1) opening a valve passage from (a) a chamber containing an incompressible metering liquid in a first chamber in contact with a first sample of a fluid source at a predetermined initial pressure through a first conduit or fixed internal diameter and length to (b) a second flexible conduit and a second upstanding chamber initially filled with a gas and (2) locating additional volume of said fluid source into said first chamber and passing a fixed portion of a volume of said incompressible metering liquid from said first chamber and said first conduit into said valve and second conduit and into said second chamber and selectively discharging from said second chamber and second conduit all of the said gas theretofore therein and thus filling said second conduit and said second chamber with said incompressible liquid, then emptying all of said added liquid from the second chamber preparatory to another cycle. The gas or liquid to be sampled passes from the source thereof through a conduit purge line for a sufficient time to purge said line from the source of any fluid theretofore therein prior to passing said additional volume of sample of said fluid into said first chamber. A unique differential valve structure automatically meters the volume of displacement measuring liquid flowing under a 125 p.s.i.g. pressure drop to within + OR - onehalf gram accuracy. The apparatuses also include a unit for selective passage of air while precisely checking flow of displacement liquid, to provide a consistent precise measure of gas or liquid sample volume and a sample receiver connection system that is readily connected and disconnected for sample handling without damage to the precision of operation of the system.

United States Patent [191 Bllfkili et al.

[ FLUID SAMPLING PROCESS AND APPARATUSES THEREFOR [75] Inventors:Guydell O. Bufkin; Thomas P. Moore, both of Amarillo, Tex.

[73] Assignee: Pioneer Natural Gas Company,

Amarillo, Tex.

[22] Filed: Nov. 15, 1971 [21] Appl. No.: 198,740

Primary Examiner-S. Clement Swisher Attorney, Agent, or Firm-ElySilverman 5 7 ABSTRACT Processes and apparatuses for automaticallysampling gases and/or liquids by the steps of (1) opening a valvepassage from (a) a chamber containing an incompressible metering liquidin a first chamber in contact with a first sample of a fluid source at aprede- [451 Oct. 22, 1974 termined initial pressure through a firstconduit or fixed internal diameter and length to (b) a second flexibleconduit and a second upstanding chamber initially filled with a gas and(2) locating additional volume of said fluid source into said firstchamber and passing a fixed portion of a volume of said incompressiblemetering liquid from said first chamber and said first conduit into saidvalve and second conduit and into said second chamber and selectivelydischarging from said second chamber and second conduit all of the saidgas theretofore therein and thus filling said second conduit and saidsecond chamber with said incompressible liquid, then emptying all ofsaid added liquid from the second chamber'preparatory to another cycle.The gas or liquid to be sampled passes from the source thereof through aconduit purge line for a sufficient time to purge said line from thesource of any fluid theretofore therein prior to passing said additionalvolume of sample of said fluid into said first chamber. A uniquedifferential valve structure automatically meters the volume ofdisplacement measuring liquid flowing under a 125 p.s.i.g. pressure dropto within tone-half gram accuracy.

The apparatuses also include a unit for selective passage of air whileprecisely checking flow of displacement liquid, to provide a consistentprecise measure of gas or liquid sample volume and a sample receiverconnection system that is readily connected and disconnected for samplehandling without damage to the precision of operation of the system.

19 Claims, 22 Drawing Figures PAIENIEBBCIZZIQI! 1 m 9 J G. O. BUF K /NAND TP. MOORE INVENTORS ATTORNEY INVENTORS GO. BUFK/N T'P. MOOREATTORNEY PAIIED M12219 WSUQ m 0 T w v 1N..

TORNE Y FLUID SAMPLING PROCESS AND APPARATUSES THEREFOR BACKGROUND OFTHE INVENTION 1. Field of the Invention The field of invention to whichthis invention pertains is measuring and testing samplers as for gasimplements therefor and gas separation with sampling or metering means.

2. Description of the Prior Art Prior art has required skilledtechnicians or highly involved machinery to draw exactly the same volumeof liquid from a bottle to permit entry of gas thereinto from a samplebottle such sample bottle containing liquid under pressure. By thisapparatus and process a different series of steps is performed so thatthe volume drawn is exact and utilizes relatively simple mechanisms andis repetitively and automatically performed.

SUMMARY OF THE INVENTION A particular synergistic combination of a valvesequence of operation, a quick release coupling which permits a checkvalve action on disconnection and a differential valve that provides fora complete removal of gas prior to providing for passage of an exactamount of incompressible liquid from a fluid sampling chamber, and anautomatic filling of the sampling chamber with precise increments ofvolume of fluid to be sampled. The flexible connection as well as theinternal structure of the valves and quick release coupling allowseffective and reliable replacement of the sample receiver assemblywithout disturbing the quantitative volumetric relations established inprevious or later cycles of operation of this apparatus system forrepeated passage from the sample source to the sample receiver of exactvolumes of fluid to be sampled.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of asystem according to this invention arranged for sampling of three fluidlines concurrently.

FIG. 2 is a rear view of the sampling assembly 21 of FIG. 1 showing, atan enlarged scale, the sample receiver assemblies 35, 235 and 435.

FIG. 3 is a diagrammatic view of the timer and control subassemblies 60,260 and 460 of assembly 21 for the three sample receiver subassemblies30, 230 and 430.

FIGS. 4, 5, 6 and 7 are diagrammatic showings of the sequentialrelations during the operations of the unit subassembly 40, comprisingone timer and control subassembly, 60, and one sample receiversubassembly, 30, operatively connected therewith.

FIG. 8A is a diagrammatic longitudinal vertical diametral section of arepresentative control valve, 56, to show some of the relations of theparts thereof and with the bottom portion of such valve exaggerated toillustrate the valve spool relations to adjacent structures, the valvespool 58 here being shown in its full elevated position.

FIGS. 8B and 8C show a view of the parts in zone SD of FIG. 8A: FIG. 8Bshows the same parts as in FIG. 8C with the valve spool 58 in its fulllowered position.

FIG. 8C is a view of parts of valve 56 as in FIG. 8B adjacent the valvespool 58 at a position of such spool intermediate between its fullelevated and full lowered position.

FIGS. 8A, 8B and 8C show for the valve 5 structure which is illustrativeof the several like valves, 26, 36, 56, 226, 236, 256, 426, 236 and 456of the assembly 21.

FIG. 9A is an enlarged view of zone 9A of FIG. 10 partly in verticaldiametral section, and shows the displacement chamber differential valve94 partly in section and partly in side view.

FIGS. 98 and 9C diagrammatically show positions of valve cap duringmotion of liquid through valve chamber 93 during the operation of valve94.

FIG. 10 is in part a side and in part a longitudinal and sectional viewof a displacement control subassembly 90.

FIG. 11 is a vertical diametral section through the orifice unit 50.

FIG. 12 is an exploded view, partly in longitudinal section of thecomponents of the bottom quick relief coupling 48.

FIG. 13 is a transverse vertical longitudinal sectional view of coupling48 in the position of its parts with locking sleeve 211 depressed, thelocking balls 133 and 133" in their release positions and the plug 127moved upward from its locked position shown in FIG. 15; this figureshows the right side of plug 127 in side view and the remainder of thecomponent and the other components in transverse longitudinal sectionalview.

FIG. 14 shows coupling 48 in the position of its parts with the lockingsleeve 211 depressed, with the locking ball 133 in its release positionand the locking ball 133" in its locking position and the shoulder 130of the plug 127 engaging the spacer plate shoulders of the valve spool196 and the valve spool 196 in its open position. This figure, like 13,shows the right side of plug 127 in side view and the other componentsof that valve in transverse longitudinal sectional view.

FIG. 15 shows the coupling (and valve) 48 in the position of its partswhen the locking sleeve 211 is in its upward, locking position, withlocking ball 133 in its locking position and valve spool 196 open. Thisfigure shows the right third of sleeve 211 in side view and shows theright half of sleeve 132 and spring 215 in side view and shows the lefthalf of plug 127 in side view and shows the other components of thatcoupling in a transverse longitudinal sectional view.

FIG. 16 illustrates the points of novelty in a modification of assembly21 for remote control of the timer and control subassembly 60.

FIG. 17 illustrates the point of novelty of another modification oftimer and control subassembly 60 of assembly 21.

FIG. 18 illustrates a modification of unit assemby 40 of assembly 21using electrically actuated valves to perform the sampling process ofthis invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The system 20 comprises thesampling assembly 21 and the fluid lines, as 22, 222 and 422 which carryand transport the fluids which are sampled automatically by the samplingassembly 21.

This fluid, (gas or liquid) sampling apparatus 21 for fluid lines 22,222 and 242 comprises, in operative combination, sample receiversubassemblies 30, 230

and 430 and timer and control subassemblies 60, 260 and 460.

The timer and control subassembly 60 controls the feeding of gas fromline 22 to the sample receiver subassembly 30 at predeterminedintervals: the sample receiver subassembly 30 comprises aself-regulating displacement control subassembly 90 and a removablesample receiver subassembly 35.

The timer and control subassembly 60 comprises a cycle initiating timerand control subassembly 100, a delay timer unit 76, and associatedvalves.

Valve units of sample receiver subassembly 30 and of displacementcontrol subassembly 90 are both operatively connected to and controlledby the delay timer unit '76 and the timer unit 100.

A timer and control assembly 260 controls the feeding of gas from line222 to the sample receiver subassembly 230 at predetermined intervals:the sample receiver subassembly 230 comprises a self-regulatingdisplacement control subassembly 290 and a removable sample receiversubassembly 235.

The timer and control subassembly 260 comprises a delay timer unit 176and associated valves as in subassembly 60 and is operatively connectedto the cycle initiating timer and control subassembly 100 of assembly60.

Valve units of sample receiver subassembly 230 and of displacementcontrol subassembly 290 are both operatively connected to and controlledby the delay timer unit 276 and the timer unit 100.

A timer and control assembly 460 controls feeding of gas from line 422to the sample receiver subassembly 430 at predetermined intervals: thesample receiver subassembly 430 comprises a self-regulating displacementcontrol subassembly 490 and a removable sample receiver subassembly 435.

The timer and control subassembly 460 comprises a delay timer unit 476and associated valves as in subassembly 60 and is operatively connectedto the timer unit 100 of assembly 60.

Valve units of sample receiver subassembly 430 and of displacementcontrol subassembly 490 are both operatively connected to and controlledby the delay timer unit 476 and the timer unit 100.

FIGS. 4, 5, 6 and 7 illustrate a form of each of the subassemblies 30and 60 which components identical to component of subassemblies 230 and260 illustrated in FIG. 3.

Accordingly, parts as 235 and 276 in FIG. 3 corresponding to the parts35 and 76 of FIGS. l-7 are identified by corresponding unit and Inumerals but higher hundred digits; eg sample receiver subassembly 235being the same as sample receiver subassembly 35 and delay timer unit276 the same as delay timer unit 76, respectively, in structure andoperation.

FIGS. 4-7 also illustrate a form of each of the subassemblies 30 and 60with components identical to components of subassemblies 430 and 460illustrated in FIG. 3.

Accordingly, parts as 435 and 476 in FIG. 3 corresponding to the parts35 and 76 of FIGS. 1-7 are identified by corresponding unit and tennumerals but higher hundred digits; e.g. sample receiver subassembly 435being the same as sample receiver subassembly 35 and delay timer unit476 the same as delay timer unit 76, respectively, in structure andoperation.

The operations and connections of timer and control subassembly 60 andthe receiver subassembly 30 are described particularly herebelow: theoperation of sub assemblies 260 and 460 are substantially the same asdescribed for timer and control subassembly 60; the operation ofsubassemblies 230 and 430 are qualitatively substantially the same asdescribed for sample receiver subassembly 30.

The unit assembly 40, which comprises the sample receiver subassembly 30and the timer and control subassembly 60, is operativelyconnected to afirst main fluid line 22 through which line passes one fluid to besampled. Line 22 is operatively attached to a tapline conduit 42 passingfrom line 22 to a cut-off valve 23. A conduit line 44 passes from thecut-off valve 23 to a mechanical filter 24 and first constant outputpressure valve 25. The first constant output pressure valve 25 isoperatively connected to a second constant pressure line 46. Line 46operatively connects via a tee 61 to a timer control subassembly feedline 62 and to a sample receiver subassembly feed line 63. The line 63passes to and through the casing 29 of a receiver control valve 26 tosupply gas (or fluid) from the line 22 which is to be received andanalyzed to the system 30 in a sequence and amount and manner controlledby the timer control subassembly 60 and in an amount controlled by thesample receiver subassembly 30. The line 62 is operatively connected tothe timer valve 66 through a constant output pressure valve 65.

The receiver valve 26 comprises a valve spool 28, and a valve controlunit 27 movable in a valve casing 29. The valve spool 28, control unit27 and valve casing 29 and orifice 174.2 of valve 26 are showndiagrammatically in FIGS. 4-7 and are, respectively, identicalstructurally to the valve spool 58, control unit 57 and valve casing 59of the valve 56 shown diagrammatically in detail in FIGS. 8A, 8B and 8Cand hereinbelow described. The casing 29 has an inlet orifice 178.2 andtwo outlet orifices 176.2 and 180.2 corresponding to orifices 178 and176 and 180, respectively, of valve 56.

One end of a chamber filler conduit line 31 connects to orifice 180.2(shown in FIG. 5) in the casing 29 and the other end of the line 31 isin series with an upper lock body 131A and a lower plug 127A of a quickdisconnect coupling and valve, 32, and, further, an upper cut-off valve,34, into the upper end of sample receiver 35, a rigid verticalcylindrical gas-tight container.

The lower end of the sample container 35 is directly connected with alower cut-off valve 45, which is connected to the end plug 127 and lockbody 131 of another lower, quick disconnect coupling 48.

The lower quick disconnect coupling 48 is connected to throttlingorifice 50 by a flexible hose line 49. Throttling orifice 50 isconnected by a stub line 51 to the orifice in the casing 59 ofdisplacement volume receiver valve 56.

The displacement volume receiver valve 56 comprises a valve spool 58,and a valve control unit 57 movable in a valve casing 59.

The valve spool 58, control unit 57 and valve casing 59 and inlet 174 ofvalve 56 are shown diagrammatically in FIGS. 4-7 and are identicalstructurally to the valve spool 58, control unit 57 and valve casing 59and inlet 174 of the valve 56 shown diagrammatically to larger scale insome detail in FIGS. 8A, 8B and 8C and hereinbelow described.

The line 62 is operatively connected to the timer valve 66 through acontrolled output pressure valve 65. The timer valve 66 comprises avalve spool, 68, and a valve control unit 67 movable in a valve casing69.

The valve spool 68, and valve casing 69 of valve 66 are showndiagrammatically in FIGS. 4-7 and are respectively identicalstructurally to the valve spool 58, and valve casing 59 of the valve 56shown diagrammatically in detail in FIGS. 8A, 8B and 8C and hereinbelowdescribed.

The valve casing 69 has two inlet orifices, 180.6 and 174.6 and twooutlet orifices 178.6 and 176.6 corresponding to orifices 180, 174 and180 and 176, respectively of valve 56.

The valve casing 69 has an outlet line orifice 178.6 to which a rigidconduit 71 is connected. The conduit 71 connects to a tee 72 and a tee82. Tee 72 is operatively connected to the delay timer unit 76 and tee82 connects to the purge valve 36 and the displacement chamber valve 56.More particularly, the tee 72 operatively connects to line 73. Line 83connects to the control orifices 174.3 and 174 in the casings of thevalves 36 and 56, respectively.

The timer delay unit 76 comprises a standard adjustable orifice 77 and aone-way check valve 78 operatively connected through a tee 79 to anaccumulator chamber 81. Line 73 is connected by a tee 74 to both thetiming orifice 77 and to a check valve 78 which (items 77 and 78) are,in turn, by a rigid tee 79 and lines 79' and 79" connected to the inletof accumulator chamber 81. The discharge end of accumulator 81 connectsby control conduit lines 84 to master pressure chamber orifice 174.2 ofreceiver control valve 26. Control conduit line 83 connects by a tee 83and a line 89 to control inlet orifice 174.3 in the casing 39 of thevalve 36 so as to move the control unit 37 thereof. The tee 88 alsoconnects to a control conduit line 85 and that control line 85 connectsby a control orifice 174 in the casing 59 of the valve 56 so as to movethe control unit 57 thereof.

The purge valve 36 comprises a valve spool 38, and a valve control unit37 movable in a valve casing 39.

The valve spool 38, control unit 37 and valve casing 39 of valve 37 areshown diagrammatically in FIGS. 4-7 and are identical structurally tothe valve spool 58, control unit 57 and valve casing 59 of the valve 56shown diagrammatically in detail in FIGS. 8A, 8B and 8C and hereinbelowdescribed.

The casing 39 has two inlet orifices 174.3 and 180.3 and one operativedischarge outlet orifice 178, corresponding to orifices 174, 180 and178, respectively, of valve 56: an outlet orifice 176.3 of valve 36,corresponding to outlet orifice 176 of valve 56 is plugged by a plug 53.

The line 64 from valve 26 is operatively connected to the inlet orifice180.3 of purge valve 36. Valve 56 comprises a rigid right conical hollowhood 151 which houses a vertical helical spring 152 which spring bottomseats on and bears against a rigid circular movable plate 153.

The volume under the hood is 151 and above the diaphragm 154 is referredto as the hood chamber 170 and it is in this chamber 170 that thecoaxial spring 152, screw plate 171 and plate 153 are located.

Plate 153 bears against an airtight flexible circular diaphragm 154 and,at the bottom of the diaphragm 154 is a bearing plate 195 which platebears against the top of spool head 186 of the spool 58.

A rigid screw plate 171 bears against the top of the spring 152 and isadjusted by an adjustable threaded screw 172 which is adjustably screwedinto a threaded hole in the top of the hood 151. The wall of the hood151 has a perforation therein, 151A for equalization of air pressure.The circular plate 153 is almost but not quite the size of the area ofthe conical hood 151 at its bottom; the diaphragm allows verticalmovement of the plate 153 up and down against the spring 152. The screwplate 171 provides a seat for the top of the spring 151 and thecompressive force in the spring 152 is adjusted by screw 172.

Below the diaphragm 154 is a master pressure chamber 173 bounded at itsbottom by a circular wall 169, with spool 58 in its center. Below thechamber 173 is located, on the left side of spool 58, a left slavechamber 175 and, on the right side of spool 58 a right slave chamber177. Immediately below the chambers 177 and 178 there is located a valvechamber 181 and, below the valve chamber 181 a bottom or lower slavechamber 179. The left slave chamber 175, the right slave chamber 177,the bottom slave chamber 179 and the valve chamber 181 are each providedwith rigid airtight walls 175W, 177W, 179W and 181W, respectively. Theleft slave chamber 175 is separable from the right slave chamber 176 atthe valve chamber top wall 182 and the right slave chamber is separablefrom the bottom chamber 179 at the valve chamber bottom wall 184. Anorifice 176 leads into the left slave chamber and orifice 178 leads intothe right slave chamber and orifice 180 leads into the lower chamber. Anorifice 174 leads into the pressure chamber 173.

The valve chamber 181 has a top wall or separation plate 182 which isprovided with a central throat or top orifice 192; the valve chamber 181at its bottom is provided with a bottom wall 184 in the center of whichis located a valve point (or bottom) orifice 194. An orifice 160connects chambers 181 and 177.

The valve spool 58 comprises in series, rigidly connected, a co-axialcylindrical spool head 186 above a narrower neck 187 with neck 187 inturn above a wide shoulder 188, which shoulder in turn is above acylindrical long spool shaft 189 which terminates at a bottom conicalvalve spool point 190. The valve spool head 186 fits tightly but movablyinto an orifice in the wall 169 between the chamber 173 and chambers 177and 175. The spool head 186 is slidably located in that orifice 185 inthat wall 169 with an air tight fit and is co-axial with the spring 152.The top of a helical spring 183 seats against the bottom of spoolshoulder 188 and the bottom of the spring 183 seats on the bottom wall184 of the valve chamber, and uses plate 184 as a spring seat andcircumscribes the valve point orifice 194 in the bottom wall 184.Orifice 194 is conical in shape.

The orifice 192 has, as shown in FIGS. 8B and 8C a vertically and lowerdepending cylindrical lip 193 which is deformable and resilient to forman air-tight fit on shoulder 188 and thereby to close the orifice 192 inthe top wall separation plate 182 between the left and right slavechambers 175 and 177 in position of parts shown in FIGS. 6 and 8Awherein the spring 183 urges the valve shoulder 188 to a lockingengagement with the lip 193 of orifice 192 and gas pressure in chamber173 cancels the downward action of spring 152. The

neck 187 is then located in the orifice 192 and the shoulder 188 islocated immediately below the orifice 192 and in a gas-tight contacttherewith. From the position of parts shown in FIGS. 8A and 6 theshoulder 188 may move away from the orifice 192 to the position of partsas shown in FIGS. 4 and 88 as below described. With gas pressure inchamber 173 removed spring 153 presses plate 195 against head 186 ofspool 58 and moves spool 58 to the position of parts shown in FIG. 8B:the spool point 190 then forms a gas-tight seal with the orifice 194 andthere is free flow from chamber 175 to 177 because of free flow throughorifice 192 in plate When the pressure in the chamber 173 exceeds thenet force of the spring 152 against the plate 153 less the force of thespring 183 against shoulder 188 of valve spool 58, the valve spool 58 ismoved upwards from the position shown in FIG. 8B to the position shownin FIG. 8A and the shoulder 188 forms a sealing contact with the lip 193of the orifice 192 while, concurrently the point 190 is removed from theorifice 194. As shown by the position of parts shown in FIG. 8A when theshoulder 188 forms a gas-tight seal with the orifice 192 there isfree'flow from orifice 180 via chambers 179,

(b) the force of spring 183 against shoulder 188 of valve spool 58 thevalve 58 is'moved downward to the position shown in FIG. 8B and theshoulder 188 loses its sealing contact with the lip 193 of the orifice192 while, concurrently the point 190 is forced into the orifice 194and, as shown in FIG. 88, forms a gas-tight seal between such pointl90'and such orifice 194 whereby passage from or to either of left slavechamber 174 and right slave chamber 177 to or from lower slave chamber179 is cut off. v

The valve hood 151 and the chamber walls 174W, 177W, 179W and 181W formand are referred to herein as a valve casing 59; the spring 152 and thediaphragm 154 and the plates 153 and 169 form and are referred to hereinas control unit 57. In summary, the movement of the control unit 57controls the movement of the spool 58 in the casing 59..

The timer initiator unit 100 comprises a notched circular timing wheel101 which is driven at a uniform rate of angular speed by a standardelectric or spring wound motor 109. A rigid arm 103 having a rigid shoulder 105 is urged toward wheel 101 by a spring 104, one end of whichspring bears against the timer frame 106 and the other end of whichspring bears against the shoulder 105 and causes the free or finger end108 of arm 103 to engage either the notch 102 or the edge 107 of thewheel 10]. The other, base, end of the arm 103 engages the spool 68 andis firmly fixed thereto. A spring 183.6, identical in structure to thespring 183 of the valve unit 56, urges the spool-68 towards the positionof parts shown in FIG. 8A, 5 and 6, when the finger end of arm 108engages the wheel notch 102; at other times in the cycle of operation ofthe timer initiator unit 100 the edge 107 of the wheel holds the arm 103and, thereby spool 68 in the position of parts shown in FIGS. 8B (forcorresponding parts of valve 56) 4 and 7. Motor 109 drives the wheel 101clockwise.

surface 92, a conical roof 96 with an upper outlet 93.1

and a lower conical wall 98.1 surrounding a chamber inlet 99. s

The valve 94 comprises a vertical cylindrical valve chamber 125 with adifferential valve sealing cap 95 therein. Chamber 125 is located in anddefined by a cylindrical chamber wall 121, a stepped top annular valveshoulder 122, a lower annular valve shoulder 123 and an upper annularvalve outlet orifice 97 in center of annular shoulder 122 and a lowervalve inlet orifice 124.

The differential sealing cap 95 comprises a valve shirt that slidablyyet closely fits the interior surface 121' of the wall 121, a perforatedconical shoulder surface 111 with equally sized and symmetricallylocated holes 112, 112', 112" and 112" and an imperforate head 114. Thehead 114 has an upper flat circular face 113 which is coaxial with andlaterally contiguous to an upper conically sloped face 115 terminatingin a lateral edge 117, which lateral edge is also the upper lateral edgeof a lower conically sloped head face 118 that terminates in a centralneck 119; edge 117 is very closely adjacent to yet spaced away (0.030inch distant) from the inner wall 121' of the chamber 93.

An elastically compressible oily rubber o-ring 1 16 is located betweenthe upper conical cap face 115 and a seat 122A on the bottom surface ofthe valve roof 122. A circular slit is located between the circularlateral edge 117 and the .inner cylindrical surface 92 of differentialvalve chamber. Slit 120 is wide enough (0.030 inch) to allow air to passthrough such circular slit. Surfaces 121', 111, 118, 115 and o-ring 116are wetted by water, hence when water passes upward through the holes112, 112', 112" and 112" through the conical surface 111, it'does notpass freely through the slit 120 between head lateral edge 117 and wallsurface 121'. As a measure of such sealing, when the valve 94, assembledas in FIG. 9A, is turned upside down and water is put into the normallylower orifice 124 and fills chamber 125, no water passes out of normallyupper orifice 97.

The slit 120 between the lateral edge 117 of cap head 114 and chamberwall 121 is deliberately large enough to allow flow of air therethroughbut, as below described prevents free the flow of displaced liquidupwards past the cap 95. With fixed pressure across slit 120 as existswhen water is flowing upward of line 91 toward valve 94 with a I20p.s.i.g. pressure in chamber Valve 94 provides as below described thatthe valve 94 will pass air upwards therethrough but no water exceptvapor and a small fixed miniscus discharge.

Quick release coupling 48 comprises an end plug 127 and a lock body 131.The end plug is movable into and out of or may be firmly locked in thelock body 131 which may act as a check valve, hence couplings 32 and 48are referred to as valves as well as couplings.

The lock body 131A and end plug 127A of quick release coupling 32 arestructurally identical, respectively, to lock body 131 and end plug 127of quick release coupling 48 but coupling 32 is upside down relative tocoupling 48. In coupling 48 end plug 127 is above lock body 131 while incoupling 32 the lock body 131A is above the end plug 127A. The bottom ofend plug 127A is connected to the top of upper cut-off valve 34 and thetop of end plug 127 is connected to the bottom of cut-off valve 35: thebottom of lock body 131 is firmly connected to the upper end of hose 49.

The end plug 127 is a rigid sleeve with a cylindrical outer surface 147and a cylindrical inner surface 148. The inner surface defines acylindrical channel 128. A circular peripherally open annular lockinggroove 129 is located on the outer surface 147; it opens outward andserves to engage a plurality of rigid locking balls 133, 133', 133",133", each of like size, shape and strength. The plug 127 terminates atits bottom (as shown in FIGS. 2, 4-7 and 13-15) in a rather wide annularshoulder 130 which shoulder operatively engages the shoulders, as 198',198" and 198" of the spacer plates, as 197, 197' and 197".

The lock body 131 is a subassembly which comprises, in general, anintermediate sleeve 132, a valve spool 196 with a spring load mechanismtherefor, a base 206, and a lock sleeve 211 in operative combination. Ingeneral, the valve spool 196 is located within the intermediate sleeve132; the sleeve 132 is removable but firmly attached to the base 206 andthe lock sleeve 211 is spring loaded on and is movable axially as wellas rotatably on the periphery of the intermediate sleeve 132. The locksleeve 211 serves to either releasably yet firmly hold or lock the endplug 127 in position whereat it engages the valve spool 196 and holdssuch spool in position as shown in FIG. whereat it does not blockpassage of fluid through the lock body 131, or the lock sleeve may bemoved to release the end plug 127 from such locked position, as shown inFIG. 13.

The intermediate sleeve 132 is a rigid cylindrical sleeve with aninterior cylindrical channel 149; an annular shoulder orifice 139 isfirmly fixed to the interior surface 146 of the sleeve 132 near themiddle of that sleeve (see FIG. 12). The sleeve 132 has smooth outer andinner wall surfaces with a plurality of axially symmetrically locatedlocking ball holes 134, 134, 134" and 134" located therein in a ringcoaxial with sleeve 132. Each of the holes as 134 is conically shapedwith the base of the cone directed radially and the apex directedcentrally, and the axis of each such conical shape is perpendicular tothe central longitudinal axis of sleeve 132. At the bottom (as shown inFIGS. 12, 13, 14 and 15) of the intermediate sleeve 132 is a laterallyor radially projecting lower, spring shoulder 136 and, at the top ofintermediate sleeve is a laterally or radially projecting upper stopshoulder 216. The outer cylindrical surface of intermediate sleeve 132is smooth, the interior surface of sleeve 132 is smooth at the top andthreaded, at 209, below the orifice shoulder 139.

The valve spool 196 comprises three rigid vertically extendingtriangularly shaped spacer plates, 197, 197' and 197" and a rigidcircular base 199. Each plate has a downwardly and laterally sloped sideedge, a bottom edge and a central end. All the central ends are firmlyjoined; each bottom edge is firmly joined to the top of base 199. Eachlaterally sloped side edge is provided, near to but definitelyvertically spaced away along the side edge from the bottom of each suchplate, a shoulder, as 198, 198', and 198 for each of the plates 197,197' and 197", respectively. The spacer plates fit freely for verticalmotion within the orifice 191 in orifice shoulder 139, but the valvespool base 199 is too large to pass upward through that orifice; in itsclosed position base 199 makes a gas-tight seal with an o-ring 139.0located at the bottom of such shoulder. The base 199 is a rigid flattruncated cone adapted to better form a gas-tight seal with the o-ring139.0 in its sealing position, as in FIGS. 14 and 7.

The base 206 comprises an externally threaded sleeve 297, a shoulder208, a spider 203 and a spring 200 in operative combination. Theshoulder 208 is firmly attached to the outside of the threaded sleeve207 for manipulation thereof. The periphery of sleeve 207 threadedlyfits into and engages the threads 209 on the bottom portion interior ofintermediate sleeve 132. A cylindrical channel 210 is located within thesleeve 207. The top of the base sleeve 207 supports a threearmed spider203; the arms as 204, 204' and 204" of the spider are axiallysymmetrical and outline the spider orifices 205, 205' and 205". Theorifices 205, 205 and 205" are continuous with cylindrical channel 210within base 206. Channel 210 is continuous with the bottom portion ofthe central channel 149 in the intermediate sleeve 132. A resilienthelical metal valve spring 200 is compressed between the base 199 of thevalve spool 196 and the spider 203 in the usual operative position ofparts of quick release coupling 48 as shown in FIGS. 13-15: in suchposition the threads of base sleeve 207 engage the threads ofintermediate sleeve 132 and the valve spool 196 is urged (when end plug127 is not locked to sleeve 132, and hence plug 127 is free to move, asin FIG. 13) into contact with shoulder 139 and forms a gas-tight fittherewith.

The lock sleeve 211 is a rigid cylindrical sleeve located axiallymovable along the peripheral surface of sleeve 132. The lower, narrowerinterior surface 212 of the locking sleeve 211 forms a smooth slidingfit on the exterior surface of the intermediate sleeve 132 and iscontinuous with an upper conically bevelled narrower portion 217. Thesleeve 211 has a lower laterally extending shoulder 214 that engages alock sleeve spring 215 that seats on the base shoulder 136 and iscompressed therebetween and forces the sleeve 211 resiliently yet firmlyupwardly therefrom. In the upwardly moved position of the sleeve 211, asshown in FIG. 14, the upward motion of the sleeve 211 is limited byengagement of the top of sleeve 211 with an upper stop 216, firmlyattached to intermediate sleeve 132. In such upwardly moved position ofthe locking sleeve 211, the narrower inner lower surface 212 of locksleeve 211 engages the locking balls as 133, 133, 133" and 133" andholds each of such balls firmly in the groove 129 of the lug 127, as inthe position of parts shown in FIG. 15 and used in FIGS. 2-6.

When the locking sleeve 211 is in its downwardly moved position as shownin FIGS. 13 and 14, the upper enlarged inner surface 217 of the lockingsleeve 211 does not force or urge the locking balls as 133, 133', 133"and 133" inwards the amount or distance that the narrower portion 212 ofthe interior surface of the sleeve 212 does as shown in H6. accordinglythe locking balls 133, 133', 133" and 133" may be moved outwards ofholes 134, 134', 134" and 134', respectively by movement of end plug 127outwards of sleeve 132. Then the plug 127 is no longer held downwards inthe chamber 149 by such locking balls, and may be freely moved out ofengagement with such balls and the sleeves, as 132 and 211.Additionally, to insert the plug 127 into chamber 149, the sleeve 211must be first moved towards shoulder 136, downwardly in F168. 13-15, tothe position of parts as shown in FIGS. 13 and 14 so that the shoulder130 may be freely moved towards shoulders of the spool 196 and past thelocking balls as 133, 133', 133" and 133'.

In the position of plug 127 wherein it is held downwards by the lockingballs 133', 133" and 133", the shoulder 130 of plug 127 engages thespacer plate shoulders, as 198, 198' and 198", as shown in FIG. 14. Thelocking balls, as shown in FIG. 15, then fix plug 127 and its lowershoulder 130 relative to intermediate sleeve 132 and the orificeshoulder 139. The engagement of shoulders 198, 198' and 198" withshoulder 130 moves the spool 196 downwards from its sealing positionwithin orifice 191 as shown in FIG. 13 to the position whereat the spoolbase 199 is spaced away from the o-ring 1390, as shown in FIGS. 14 and15: in such (FIG. 14) position of spool 196, the valve channels, as 201and 201' between the spacer plates 197, 197" and 197", respectively,(and a third valve channel between spacer plates 197 and 197 which thirdvalve channel is not illustrated) provide free passage for fluid; e.g.gas, between the portion of chamber 149 above the orifice shoulder 139and the portion of chamber 149 below that shoulder (and vice versa).

Accordingly, when the plug 127 is locked by the balls 133, 133', 133",and 133' in the position thereof shown in FIG. 15, the control channel128 of plug 127 is in open communication with the upper portion ofchannel 149 and the orifice 191 in shoulder 139, and through the valvechannels, as 201 and 201' of spool 196 to the channel 210 of the base206 and the lock sleeve spring 215 firmly yet resiliently holds thesleeve 211 in position against the locking balls so such opencommunication is maintained. When, however, the locking sleeve 211 ismoved downward towards shoulder 136 against the force of spring 215until the locking balls may be moved laterally out of engagement withthe peripheral locking groove 129 on plug 127, as shown on left side ofFIG. 14, and in FIG. 13, the plug 127 is removable from the lock body131 and, with such removal, which occurs manually in less than 0.2second, the valve spool base 199 comes into sealing engagement with theshoulder o-ring 139.0 and prevents passage of fluid upward through basechannel 210 and chamber 149 of intermediate sleeve 132.

The timer unit 100 and assembly 21 are supported on a standard 140: thehousing of timer frame 106 is firmly attached to a vertical standard142: an upper deck frame 141 is attached to and supported on housing 106and timer assemblies 76, 276 and 476 are attached thereto and assemblies35, 235 and 435 are suspended therefrom: a lower rigid frame 145supports the displacement control subassemblies 90, 290 and 490;

each of the flexible hoses 51, 251 and-451 are supported from an upperend adjacent the quick disconnect couplings 48, 248 and 448. v

The orifice unit 50 comprises a threaded male and female fitting havinga skirt 156 and a head 1S8 joined at a shoulder 157 with a narrowstraight smooth walled cylindrical channel 159 extending through theshoulder. Channel 159 has a much smaller diameter than the lines 51 and49 to which unit 50 is connected. A female thread in skirt 156 jointflexible hose line 49 and the head 158 has a male thread joined to avery short line 51 passing to orifice 180 of valve 56.

The operation of this system 20 is here described as starting where thesampling apparatus 21 is in the position of parts thereof whereat nosampling is occurring and the system 20 is prepared to begin a cycle ofrepeated periodic sampling from each of a plurality of conduits, as 22,222 and 422 containing fluid passing therethrough each with pressure inexcess of atmospheric. The operative positions of the valve bodies as28, 38 and 58 and 68 of valves 26, 36, 56 and 66, respectively, are thenshown in H0. 4. Chamber 35 is then filled with a liquid that ispractically incompressible and has no appreciable capacity to dissolvethe components of the fluids sampled-eg. water in case of hydrocarbongaseous mixtures, and mercury where water-soluble components, as H S andwater vapor, might be met.

Prior to initiation of the sampling procedure the timer unit 100 islocated so that the edge 107 of the timer wheel 101 contacts the springloaded arm 103 and holds the valve spool 68 of the valve 66 in theposition of parts shown in FIGS. 4 and 83.

Gas under pressure of line 22 then passes from the line 22, through line42, usually at a pressure of over 125 p.s.i.g. to the open mainlinecut-off valve 23 and line 44, trash filter 24 and constant outputpressure and reducing valve 25 where its pressure is reduced to 125p.s.i.g., thence via line 46 to the tee 61 and, therefrom (a) via line62 and a second constant output pressure valve 65 to orifice 180.6 ofvalve casing 69 of valve 66 and (b) via line 63 to and through theorifices 178.2

and 180.2 of valve 26 and line 64 to orifice 180.3 of

purge valve 36 to plug 53.

Initiation of the sampling procedure for each incremental addition ofsampled gas to the container 35 after the first, is by steps ofoperation of the sampling apparatus 21 as follows.

The timer unit 100 is turned by clock 109 so that the notch 102 of thetimer wheel 101 receives and contacts the finger end 108 of the springloaded arm 103. The spring 183.6 then moves the spool unit 68 of thevalve 66 to position of valve parts shown in FIGS. 5 and 8A for spool58.

This permits the to-be-sampled fluid (or gas) under 1 pressure flowwhich had theretofore been blocked by the valve spool 68 of the valve66: the fluid passes through the chambers (as 179 and 177 of valve 56)in the valve 66 to the conduit line 71 and, therethrough, to the tees 72and 82. From tee 72 the fluid (or gas) flows rapidly but at a controlledrate through the adjustable orifice 77 and not at all through the checkvalve 78.

The control valve 26 comprises a valve spool 28 and a valve control unit27 movable in a valve casing 29.

The valve spool 28, control unit 27 and valve casing 29 of valve 27 areshown diagrammatically in FIGS.

4-7 and are respectively identical structurally to the valve spool 58,control unit 57 and valve casing 59 of the valve 56 showndiagrammatically in detail in FIGS. 8A, 8B and 8C and hereinbelowdescribed.

Accumulator chamber, 81 (as 281 and 481) fills over a predeterminedperiod of time with gas (from valve 65) at a predetermined pressure inthe common manner for timing devices of this type and, after suchpredetermined time, which time is determined by adjustment of orifice 77in view of length of line 44 from line 22 to valve 26, the gas inaccumulator chamber 81 reaches a sufficiently high pressure to overcome(via line 84) the spring loading of control unit 27 (against spool 28)in the valve 26 and causes the valve spool 28 to be rapidly moved intothe position thereof shown in FIGS. and 8A.

During the predetermined period of time in which gas is (a) passing intothe accumulator 81 and (b) passing from the accumulator 81 into thechamber within the valve casing 29 at a pressure insufficient to movespool 28, gas is also passing from the tee 82 via lines 83 and orifice174.3 directly into the master chamber orifice 174.3 within the valvebody 39 of the valve 36 and rapidly moves the valve body 38 in valve 36from the position thereof shown in FIG. 4 (and for a like valve 56 inFIG. 8B) to the position therefor shown in FIGS. 5 and 8A. This,accordingly, provides for the connection of the orifices 180.3 and 178.3and the conduit 64 and the discharge of gas from mainline 22 to lines44,

" 63 and 64 for a time sufficient to clear the line 44 of any and allfluids theretofore remaining in such line 44 from any previous samplingprocedure of line 22.

In a valve as 56, adjustment of the adjustable threaded screw 172adjusts the compressive force of spring 152 against the movable plate153; such adjustment is also provided for in each of the valves 26, 36and, in the variation shown in FIG. 16, in valve 666.

During the period of time (determined by setting of adjustable orifice77 for assembly 60) prior to accumulator 81 filling at a pressuresufficiently elevated to move spool 28 of valve 26 valve 56 is connectedas shown in FIG. 5, but valve 26 is connected, as shown in FIGS. 4 and 5as gas passed by valve 26 to tee 82 passes to chamber 174 of valve 56and causes spring 153 to be compressed and valve spool 58 to move upwardfrom its position shown in FIG. 88 to the position thereof shown in FIG.8A.

When valve 56 is in position of parts shown in FIGS. 8A and 5, liquid135 flows from chamber 35 into line 49 and past orifice 150 intochambers 175, 181, 177 and line 91 and displacement chamber 92 and valvechamber 121; the initial pressure is the pressure of the line 22 orvalve 25, usually 125 p.s.i.g. applied to top of liquid in chamber 35and this is sufficient to very rapidly fill line 91, and chamber 92 and94. While the liquid 135 pours into the chamber 92 it drives the airtheretofore therein upward ahead of the top surface of such advancingliquid; also, the air theretofore in line 91, chambers 92, 177 and 181is driven to and escapes through the slit 120 and holes 112, 112', 112"and 112" of cap 95. The roof head 114 stops spray from passing out oforifice 97 with the escaping air and the slit 120 and wall 121 preventsdroplets carried through holes, as 112 and 112' from passing outward ofoutlet 97 with such air flow. When liquid first reaches slit 120 as inFIG. 98 a miniscus 126 forms as in FIG. 9B while cap is moved upward toposition of FIGS. 9A and then 9C.

The circular surface 113 of the head 114 above conical surface 115 isslightly smaller in diameter than the area of the circle at whichcontact is made between the o-ring 116 and the surface 115. Accordingly,the corresponding central portion 126C of the volume of the liquidmeniscus central of that circle of contact at position of cap 95 in FIG.9B, is separated from the remainder of the miniscus in the closedposition of cap 95 shown in FIG. 9C; the volume of such separatedportion is the same at any cycle of operation of the subassembly 30 andis popped out of the orifice 97 by the impact of head of cap 95 ono-ring 116 of valve 94.

The volume of liquid cut off by o-ring from surface 115 is driven out oforifice 97. This is a fixed amount and guarantees no air is entrapped inchamber 93 or valve 94. Otherwise expressed, the superatmosphericpressure of gas above the liquid in chamber 35 drives a predeterminedyet fixed quantity of such liquid through the slit 120. As the pressureof the driving gas above the liquid in chamber 35 is the same in allcycles of the operation, and as the restricting orifices 151 is thesame, and the valve cap 95 starts moving upward at a fixed part in theoperation (of discharge of liquid from chamber 35 to displacementchamber 22 and valve chamber 122) only after the top surface of theliquid displaced from chamber 35 and line 49 reaches the inlet 124 tothe valve 94, the amount of liquid discharged through orifice 97 is thesame in all such cycles of operation. The volume of liquid drawn fromchamber 35 during each such step of movement of valve 56 from itsposition shown in FIG. 4 to position shown in FIG. 5 to connect line 41and chamber 93 is the sum of volume of the liquid flowing into andfilling the displacement chamber 93, valve chamber 94, pipe 91 valvechambers 181, 179 and 177 and leaks. Such volume is drawn from thevolume of liquid therefore in chamber 35 and in hose line 49.

The volume of liquid passing into line 91 during the period of the cycleof operation of unit subassembly 40 between the stages shown in FIGS. 5and 6 is drawn from the (a) line 49 and (b) interior volume of samplereceiver chamber 35 and (c) the chambers 181, 179 and 177 in valve 56.This amount is reduced by any amount of leakage that occurs during any*teeter" stage when the spool 68 is in the position shown in FIG. 8C; atsuch position (shown in FIG. 8C) the valve orifice 192 in plate 182 isopen and the bottom valve orifice 194 in bottom plate 184 is open.

As below described the amount of liquid discharged in such stage isfixed and small notwithstanding that during the portion of the cycle ofoperation of valve 56 wherein liquid flows from line 91 to the valveoutlet 176 of the valve 56 water passes through orifice 192 to chamberand partially fills the chamber 181 to the level of the orifice 192, theaxis of chamber 181 of the valve 56 (as well as 256 and 456) then beinghorizontal, as shown in FIGS. 1 and 2. As conical point is blunt andslotted, a possible teeter period as in FIG. 8C is extremely briefbecause the structure of valve 56 provides that there clearly is reliefof some force of spring 152 on plate 153 and consequent relief of someforce of plate 195 on the head of spool 68 prior to the valve spoolpoint 190 being at all moved from its blocking or sealing relation tothe lower valve orifice 194. Also, the spring 152 is very long (about 2inches) relative to the total movement of valve spool 58 from positionshown in FIG. 813 to that shown in FIG. 8A (about one-sixteenth inch) inthe particular embodiment used and so avoids any increase in pressurerequired to close the valve orifice 192 once plate 195 begins to reduceits force of contact with the head of spool 68.

Also, the interchamber orifice 160 between chambers 177 and 181 is acircular segment (portion of a circle bounded by an arc and its chord)with a length (along chord) of one-half inch and a width (from chord toarc) indicated as 161 in FIG. 8B of three-sixteenth inch, while orifice192 is only three-sixteenth inch diameter. Accordingly, liquid flowsmore readily from orifice 180 of valve 56 to and through such orifice160 than through the smaller sealing orifice 192 and such liquiddevelops no substantial pressure against the orifree 192 during initialperiod of flow from orifice 180 to 160.

The valve 56 also provides a large increment of movement of spool 68during the period of a small increase in pressure in line 85 (connectedto orifice 174 of valve 56) because of the exposure of the face of thepoint 190 to the fluid under pressure from line 49 at the time that theorifice 194 closing action of spring 153 is overcome by the gas pressurein line 85 whereby the force with which the spool is urged towardsorifice 192 is increased by the added area at the blunt spool pointacross which such liquid pressure is applied while the bulky helicalspring 153 in combination with the bulky shaft 189 blocks initial directflow of liquid from orifice 184 to 192.

The time for the short movement of the spool shoulder 188 to make asealing contact with orifice 192 is brief, no more than about one-fifthsecond, and other forces creating such movement; e.g. pressure of waterin line 49, pressure of gas in line 85 are constant; e.g. the volume ofliquid entering chamber 181 prior to closing of the orifice 192 by theshoulder 188 is limited by the size of orifice 194 and pressure in line49 and size of chamber 181; the orifice sizes and chamber size are fixedby the structure of the valve 56: the pressure on the liquid in line 49is determined by the pressure of the gas 168 in chamber 165 which gaspressure is fixed by the constant output pressure valve 25. The movementof spool 68 is a rapid snap" action while the liquid flowing through theorifice channel 159 of orifice unit 50 is throttled and accordinglyflows through such orifice channel at an even rate of flow to and thencethrough orifices 180 and 184 of valve 65 slowly to orifice 192.

Accordingly, as the period of time during which both orifices 192 and194 are open is short and the same in each cycle, only the same amount(about 0.2 grams) of liquid is discharged from valve 56 during each suchstep of transferring liquid from chamber 35 and line 49 to chamber 92and line 91. As line 91 is a dimensionally stable hose I500 p.s.i. test,wire braid reinforced) and the liquid in that hose fills that hose atall times only a fixed and predetermined volume of liquid passes out ofchamber 35 during each cycle of operation to chamber 92 and 94, line 91,valve chamber 177 and to the there tofore unfilled portion of valvechamber 181, as well as to provide discharges of small yet fixed amountfrom outlets of valves 94 and 56.

After the accumulator chamber 81 is filled with gas at a pressuresufficiently raised to effect the movement of spool 28 of valve 26 fromits position shown in FIG.

4 (and in FIG. 8B for the like spool 58) to the position of the spool 28shown in FIG. 5 (and in FIG. 8A for the like spool 58), the resultingmovement of the valve spool 28 serves to connect orifices 178.2 and180.2 of valve 26 in manner shown for connection of orifices 178 and 180in FIG. 8A. Conduit 63 is thereby then connected to the line 31 andpasses gas from line 22 under the constant pressure as provided for bythe constant output pressure valve 25 (or of the line 22 if there is nosuch constant pressure output valve) through the quick disconnectcoupling 32 thence through cut-off valve 34 to the sample container 35chamber 165.

The pressurized, gas passing into line 41 from valve 26 occupies thevolume of the liquid in chamber 165 theretofore passed from that chamberinto line 49 and 91, valve 56 and to displacement control subassembly90. The displacement control subassembly 90, once filled with apredetermined amount of incompressible liquid, prevents further entry ofgas into chamber 165, and the pressure in chamber 35 rises and reachesthat of the constant output pressure valve 25, leaving a gas sample inchamber 165.

When the period of sampling is over the valve control wheel 101 movesfrom the position thereof shown in FIGS. 5 and 6 to the position thereofshown in F IG. 7. In this position the spool 68 of the valve 66 is movedleftward from the position shown in FIGS. 4 and 5 to the position shownin FIG. 7. In this position the spool 68 is moved to the positionwhereat orifices 176.6 and 178.6 communicate with line 71 andaccordingly exhausts such line. The exhaustion of such line provides forthe release of pressure against the valve control 37 and the movementthereof from the position shown in FIGS. 5 and 6 to the position shownin FIG. 7 in which position no further gas or fluid passage occursthrough the line 64. Concurrently, there is flow from the accumulator81, which is under pressure, to and through the check valve 78 and thento and through the line 73, tee 72 and line 71 likewise to exhaustthrough the valve 66. This exhaust of gas under pressure from theaccumulator 81 causes the valve control unit 27 of the receiver valve 26to return from the position shown in FIG. 6 to the position thereofshown in FIGS. 4 & 7. This return is accomplished by the conventionalspring loading (as 152 in valve 56) of the valve control unit 27. Thismovement of the control unit 27 moves the spool 28 so that the line 63no longer connects to the line 31 and further flow from the line 22 tothe chamber 35 is terminated. At the same time the spool 28 of the valve26 is connected to the line 64 for a subsequent purging step in asubsequent sampling cycle.

Concurrent with the movement of the valve spool 28 to the position shownin FIG. 7 the pressure in line 85 to control unit 57 of the valve 56also bleeds through to the line 71 to exhaust and valve body 58 is movedfrom the position shown in FIG. 5 to the position thereof shown in FIGS.4 and 7.

In the position of the valve body 58 shown in FIG. 7 the body of liquid166 in chamber 92 escapes through line 91 and the valve 56 to a meteringliquid holder 167. This passage of the metering liquid provides that thecap 95 sinks to the bottom of the chamber therefor and air passesthrough the opening 97 in the roof of the chamber 125 and holes 112,112, 112" of cap 94.

The volume of chamber 92, line 91 and some passages of valve 56 areaccordingly thus filled with air in the position of parts shown in FIGS.4 and 7. However, in the position of FIGS. 5 and 6 a portion of themetering liquid 135 discharges into that volume, displacing the airtheretofore occupying such volume and providing a discharge at valves 94and 56. The volume of this portion of the discharged metering liquid isa highly accurately reproduceable volume and provides for a highlyreproduceable displacement volume so that the amount of gas taken in ateach increment of sampling is identical to the volume taken in at anyother increment of sampling. The pressure of each such increment islikewise the same during any increment of sampling and the temperatureof the gas is recorded so that appropriate corrections may be taken forsuch variation as may be the result of any temperature variation.

The base 206A of the lock body 131A of quick disconnect valve 32 is thesame structure as base 206 of lock body 131 of quick disconnect valve48. The shoulder of base 206A of locking body 131A is firmly attached tothe bottom of conduit line 31. The end of plug 127A distant from itsfree annular shoulder 130A is firmly attached to the top of uppercut-off valve 34 of the sample receiver assembly 35.

End plug 127A is operatively connected to lock body 131A of valve 32 inthe same manner as end plug 127 and lock body 131 of valve 48 areconnected as above described and shown in FIG. during the abovedescribed operationof unit 40 of apparatus 21.

After one or several cycles of operation of the unit assembly 40 asabove described in relation to FIGS. l-l l and a corresponding passageof one or several increments of gas into the interior 165 of chamber 35and passage of corresponding amount of liquid 135 out of the interior ofthe chamber 35 cut-off valves 34 and 45 are closed tightly and the locksleeve 211 of lock body 131 of quick release valve 48 is moved towardthe base 206 to release the end plug 127 from the lock body 131 as abovedescribed in relation to FIGS. 12-15. Immediately thereafter the lockbody and the upper end of the flexible hose line 49 attached to thatlock body are carefully moved downwardly from the end plug 127, theupper end of which is firmly attached to the lower end of cut-off valve45 (which is firmly attached to chamber 35).

The valve spool 196 then automatically and immediately seals off theorifice 191 in plate 139 of sleeve 132 and maintains in line 49 andvalve 56 and in chamber 150 above shoulder 139 the displacement liquid;e.g. water-theretofore completely filling that line to the inlet ofvalve 56 and the chamber 175 in the valve 56. The flexibility of line 49permits this release of the valve 48. The structure of valve 48 providesfor maintaining the liquid between volume chamber 165 and locking orsealing shoulder 188 of spool 68 of valve 65 available for the nextcycle of operations using another sample receiver assembly as 35. Aftersuch separation the lock body is maintained with its sleeve 132 andlocking sleeve vertical and the pyramidal shaped valve body 196 pointedupward but moved out of alignment with longitudinal axis of chamber 165of sample receiver 35, so that such receiver may be later moveddownwards for replacement.

After the closure of valves 34 and 45 followed by disconnection of lowerquick disconnect valve 48 from lower cut-off valve 45, the upper quickdisconnect valve 32 is disconnected from the upper end plug 127A. Thisdisconnection is accomplished by moving the lock body sleeve 211Aagainst the force of spring 215A (which spring corresponds to spring 215of quick disconnect valve 48) toward the base 206A to release the endplug 127A from the lock body 131A. Immediately thereafter the end plug127A and the sample receiver assembly 35 to which attached are carefullymoved downward from the chamber of lock body 131A (corresponding tochamber 149 of lock body 131 above shoulder 139).

The valve spool of valve 32 corresponding to spool 196 of valve 48 thenimmediately and automatically seals off the orifice such as 191 in plate139 of sleeve 132 and maintains in line 31 the fluid---e.g. gas to besampled---theretofore completely filling that line and the chamber, as175 in valve 56, to which such line is connected. The structure of valve32 provides for maintaining the gas (of known composition) available forthe next cycle of operation using another sample receiver as 35.

Each thus separated sample receiver, as 35, is replaced by another likereplacement sample receiver, as 735, wherein the interior chamber(corresponding to is filled with water from and including valve 734 toand including valve 745 (corresponding to valves 34 and 45) and, alsothe volume of channel 128 in plug 127 of valve 48 is filled with waterand the plug 127A of valve 32 is filled with water (or otherdisplacement liquid used in 165) while the lock body 131 of valve 48 andthe end of flexible hose line 49 attached thereto are moved out of theway of or out of the space theretofore occupied by sample chamberassembly 35. The lock body 131A of quick disconnect valve 32 attached tothe conduit 31 is then attached to the upper end plug, as 727A of thereceiver 735. Plug 727A is identical to plug 127A in structure and isattached to cut-off valve 734 as plug 127A is attached to cut-off valve34.

The lower ,end plug 727 of sample receiver 735 is then attached to thelower lock body 131 of quick disconnect valve 48.

This convenient and rapid exchange of a sample receiver subassembly 735ready to be filled with gas to be sampled for the sample receiver 35filled as above leaves the replacement sample receiver subassembly inthe identical condition as was sample receiver 35 when it was placed inoperative connection in the assembly 21; the receiver assembly 735, likereceiver assembly 35, comprises a standard sturdy metal gas-tightcylindrical gas cylinder tube 163 with rounded narrower upper end 162and a like rounded narrow lower end 164 and aninterior chamber 165 andan upper gastight cut-off valve 32 and a like lower gas-tight cut-offvalve 45. An end plug 127A for a quick release valve 32 is firmlyconnected to the top of valve 34 and an end plug 127 for a quick releasevalve 48 is firmly connected to the bottom end of bottom cut-off valve45. The chamber 165 and channels through valves 32 and 45 and plugs 127and 127A are filled with water prior to connecting the assembly 35 tolines 49 and 31. The attachment of lock body 131A to plug 127A supportsthe sample receiver subassembly 35 and the end of line 49 attachedthereto. Similarly the attachment of lock body 131A to plug 727Asupports the replacement sample receiver subassembly 735 and the line 49attached thereto.

The process of sampling is illustrated for gas from a natural gas line22, line 22 passing to sample receiver 35 wherein a fixed volume of apractically or substan tially imcompressible liquid---water---135 isremoved prior to each communication of such gas to the sample receiver.The liquid has no absorbent capacity for the gas components beingmeasured, or can be made so, as by acidifying where the gas has acidcomponents, as H 8, or alkalizing where alkaline components, as ammonia,are expected. Other incompressible liquids may be used; e.g. oils whereno oil-soluble components are expected, low freezing liquids for gasessampled at low temperature, high boiling liquids for sampling of gasesat high temperatures, as alcohol and mercury.

So long as the fluid passing into the sample chamber is unreactive withthe liquid used to measure and control the displacement of the samplethe fluid sampled need not be a gas. The apparatus 21 for instance wouldsample a stream of gasoline or oil, with the liquid 135 not passing intothe chamber 93 until the orientation of parts shown in FIG. 6 and, atthat time the volume of fluid flow from the line (e.g. line 222)containing such fluid would flow into the container therefor; e.g. 235,in a quantity determined by the volume of liquid 135 displaced into avalve chamber, as 179 and 181 of valve 56, a line 291 (like 91) and achamber 290 and the differential valve therefor (identical to chamber 93and the differential valve 94 therefor).

In operation of the apparatus 21, prior to drawing the first sample ofgas through chamber 165 of receiver 35 (or 235 or 435) water (or otherliquid used as the displacement liquid 135) is passed into chamber 93from valve 94 towards line 91 and valve 56, to pass through chambers 177and 175 and 179 in the position thereof shown in FIGS. 4 and 8A so as tofill chamber 179 to the level of orifice 192 and so insure that thevolume received by line 91, valve 56 and chamber 93 and 94 from chamber165 is the same as in succeeding sample increments passed to chamber165.

The o-ring 116 is composed of a cylindrical length of elasticallycompressible solid water-insoluble rubber or plastic rod formed into acontinuous ring: the ring fits snugly enough within wall 121' to supportitself by its elastic fit against wall 121. The o-ring 116 has anunrestrained outer diameter larger than the internal diameter of chamberwall 121: a vertical transverse cross section of the curved rod islonger vertically when in place below roof 122 than horizontally (asviewed in FIG. 9A). (i.e., somewhat oval rather than circular insection). When the pressure of liquid in chamber 165 (usually about 125p.s.i.g. in the preferred embodiment) is applied against cap 95; thevertical length across the transverse section (as shown in FIG. 9A) ofthe rod changes shape to be horizontally wider than long (vertically):this rapid distortion rapidly extends the line of contact of o-ring 116and face 115 centrally and, because of the obtuse angle of flat face 113with conical face 117 as illustrated in FIG. 9A rapidly displacescentrally the portion of liquid 135 theretofore immediately central ofthe line of contact of o-ring 116 and conical face 115 and separates itfrom face 115 and 113.

In the preferred embodiment of system 20 the size of lines 22, 222 and422 is usually 12 to 24 inches in diameter; lines 42, 44, 46, 62, 63,71, 83, 84, 85, 89 and 91 are one-fourth inch i.d. tubing. Orifice 150has a length of three-eighths inch and a diameter of from 0.04 to 0.06inch.

Accumulator chamber 81 is 1 8 cu. in capacity; where there is a distanceof 30 feet from line 22 to valve 26 of assembly 21, the adjustableorifice 77 as set for a 5 second period of operation of purge operation(as shown in FIG. 5) prior to connecting line 22 to chamber 165.

The motor 109 is a spring actuated mechanically wound clock that iswound each time the sample receiver chamber 35 is replaced. The periodof operation of assembly 21 in the position of parts shown in FIG. 6needs only be 2 to 5 seconds for the above described operation ofapparatus 21 with dimensions and operating conditions as in thepreferred embodiment for use with gas of analysis as in Table I andwater as the liquid I35; 3 seconds is the preferred time.

In the preferred embodiment of apparatus 40 the chamber 163 in assembly35 has a volume of 5,000 mi]- liliters between cut-off valve 34 andvalve 45 and, when filled with water weighs 30 pounds.

The volume of chamber 93 is 115 cc.

The volume in chambers 179, 181 and 177 is 7 cc. total.

The volume 124.1 in valve 94, including nipple 124.2 below shoulder 123is 3 cc.

The pressure into valve 25 is usually I50 p.s.i.g., the output pressureat 61 is set at 125 p.s.i.g.: the pressure in line 71 is reduced to aconstant 15 p.s.i.g. by valve 62.

Particular dimensions of components of a preferred embodiment ofdifferential valve 94 are set out in Table I herebelow while thequalitative relations and features of the components of such valve andits process of operation are above described.

Table I DIMENSIONS OF VALVE 94.

Cup 95 Weight 1% grams Skirt l 10 Outside diameter .3075" Length, bottomto bottom of surface 1 l l .330"

(PLA)* Thickness .020" Holes H2. H2, 112". diameter .080" Diameter ofedge II? P (NLA)* .247 Diameter of face 113 (NLA) .l6" Neck I19.diameter (NLA) .l6" Face 1 [5. length along edge .050" Face I 18, lengthalong edge .09" Face 1 I 1, length along edge .09" Angle of face 1 l5PLA 60 Angle of face I I8 PLA 30 Angle of face lll PLA 30 Ring l 16thickness of core PLA .070 Ring orifice diameter (unrestrained) FLA .020Ring outside diameter (unrestrained) PLA .034 Chamber I25. height,shoulder 123 to roof 9/16 I22 PLA Inside diameter. walls lZl (NLA) .3085Inlet I24 length of nipple (chamber l24.l) #6" Outlet 95 internaldiameter (NLA) .20"

FLA Measured parallel to longitudinal axis of skirt I10 'NLA Measurednormal to longitudinal axis of skirt cess of operation are abovedescribed.

Table II VALVE 56, CHAMBER I81 DIMENSIONS.

Chamber 181 Length. top of 184 in FIG. 14 to bottom of I82 DiameterSpring I83

1. A sampling apparatus for connection to a fluid source and comprising,in operative combination a sample receiver subassembly, a timersubassembly, and fluid flow control subassembly; a. the sample receiversubassembly comprising i. a first gas-tight rigid sample container withan opening near the bottom thereof, a lower cut-off valve at said bottomopening, and another opening to said container and another cut-off valveat said opening, and ii. a rigid walled second chamber extendingupwardly from a third valve, an upper outlet in said chamber at theupper end thereof, a lower orifice in said second chamber at the bottomthereof, differential valve means in said upper outlet having a passagefor passing gas freely therethrough but preventing free passage ofliquid therethrough and movable to seal passage of liquid therepast; b.the fluid flow control subassembly comprising, i. a constant outputpressure output valve connected to a first conduit for connection tosaid fluid source, ii. a first valve with a first inlet connected to theoutput of said constant pressure valve, a first spool in said firstvalve and first spool positioning means in said first valve resilientlyyet firmly holding said spool in a first position with the first outletof said first valve being operatively connected to the first inlet of asecond valve, and disconnected from a second outlet of said first valve,said second outlet of said first valve connected to the upper cutoffvalve of said another cut-off valve of said sample receiver subassembly,iii. a second valve with a first inlet connected to said first outlet ofsaid first valve, a second spool in said second valve, spool positioningmeans in said second valve connecting said inlet of said second valve toa blocking means, iv. a bottom coupling connected to said samplereceiver bottom cut-off valve; v. a third valve with one inlet connectedto said bottom coupling through a flexible constant volume conduit andan orifice therebetween and a second inlet connected to the lowerorifice in said second chamber, third spool means in said third valve,third spool holding means in said third valve holding said third spoolmeans in a first position whereat the second inlet thereof is connectedto a second outlet and said second outlet is connected to the atmosphereand said second inlet and said one inlet are disconnected from eachother; c. timer means operatively connected to the spool means of saidsecond and third valves and to a time delay means connected to saidfirst valve means spool, said control means operative to i. at a firststep, simultaneously move said second spool in said second valve toconnect the first inlet of said second valve to the atmosphere, and movesaid third spool in said third valve means to a second position toconnect said first inlet of said third valve and the bottom cut-offvalve and the one inlet connected to the lower orifice of said secondchamber and disconnect the lower orifice of said second chamber from theatmosphere, and said third spool means in said third valve blockingconnection between said lower orifice of said second chamber and saidatmosphere when sAid control means moves said third spool in said thirdvalve to said second position to connect said lower orifice of saidsecond chamber to said lower outlet of said first sample container, andii. at a second step, through said time delay means, move said firstspool in said first valve means to connect the first inlet of said firstvalve and the outlet of the constant pressure valve to the other cut-offvalve of said sample receiver assembly.
 2. Apparatus as in claim 1wherein said lower coupling has a check valve means preventing fluidflow therethrough from and to said one inlet of said third valve onrelease of the connection between said flexible conduit and said bottomcut-off valve of said sample receiver.
 3. Apparatus as in claim 2wherein said upper coupling has a valve means preventing fluid flowtherethrough on release of connection of said first valve second outletand said sample receiver upper cut-off valve.
 4. Apparatus as in claim 3wherein said differential valve comprises valve chamber with a lowerinlet and an upper outlet and a vertical side wall and a movable pistonin said chamber, said piston having a skirt slidably fitting the chamberwalls and a perforated yoke above said skirt and an imperforate plateabove said yoke and attached thereto, perforations in said yoke, a valveorifice in said chamber roof, said plate being larger than said orificeand, in one, elevated, position thereof, in gas-tight sealing relationtherewith, said plate edge being spaced a greater distance further fromsaid chamber wall than said skirt and a lesser distance than the size ofsaid perforations in said yoke.
 5. A sampling apparatus for connectionto a fluid source and comprising, in operative combination a pluralityof sample receiver subassemblies, timer means, and fluid flow controlsubassemblies; a. each sample receiver subassembly comprising i. a firstgas-tight rigid sample container with an opening near the bottomthereof, a lower cut-off valve at said bottom opening, and anotheropening to said container and another cut-off valve at said opening, andii. a rigid walled second chamber extending upwardly, an upper outlet insaid chamber at the upper end thereof, a lower orifice in said secondchamber at the bottom thereof, differential valve means in said upperoutlet having a passage for passing gas freely therethrough butpreventing free passage of liquid therethrough and movable to sealpassage of liquid therepast; b. each fluid flow control subassemblycomprising, i. a constant output pressure output valve connected to afirst conduit for connection to said fluid source, ii. a first valvewith a first inlet connected to the output of said constant pressurevalve, a first spool in said first valve and first spool positioningmeans in said first valve resiliently yet firmly holding said spool in afirst position with the first outlet of said first valve beingoperatively connected to the first inlet of a second valve, anddisconnected from a second outlet of said first valve, said secondoutlet of said first valve connected to the upper cut-off valve of saidanother cut-off valve of said sample receiver subassembly, iii. a secondvalve with a first inlet connected to said first outlet of said firstvalve, a second spool in said second valve spool, positioning means insaid second valve holding said second spool means in a first position toconnect said inlet of said second valve to a blocking means, iv. abottom coupling connected to said sample receiver bottom cut-off valve;v. a third valve with one inlet connected to said bottom couplingthrough a flexible constant volume conduit and an orifice therebetweenand a second inlet connected to the lower orifice in said second chamberthereabove, third spool means in said third valve, third spool holdingmeans in said third valve holding said third spool means in a firstposition whereat the second inlet thereof is connected to a secondoutlet and said sEcond outlet is connected to the atmosphere and saidsecond inlet and said one inlet are disconnected from each other; c.each timer means operatively connected to the spool means of one of saidsecond and third valves and to a time delay means connected to one ofsaid first valve means spool, said timer means operative to i. at afirst step, simultaneously move said second spool in said second valveto connect the first inlet of said second valve to the atmosphere, andmove said third spool in said third valve means to a second position toconnect said first inlet of said third valve and the one inlet anddisconnect the lower orifice of said second chamber from the atmosphereand said third spool means in said valve blocking connection betweensaid lower orifice of said second chamber and said atmosphere when saidcontrol means moves said third spool in said third valve to said secondposition to connect said lower orifice of said second chamber to saidlower outlet of said sample receiver chamber, and ii. at a second step,through said time delay means, move said first spool in said first valvemeans to connect the first inlet of said first valve and the outlet ofthe constant pressure valve to the other cut-off valve of said samplereceiver assembly.
 6. Apparatus as in claim 5 wherein each said lowercoupling has a check valve means preventing fluid flow therethrough fromand to said one inlet of said third valve on release of the connectionbetween said flexible conduit and said bottom cut-off valve of saidsample receiver and wherein said upper coupling has a valve meanspreventing fluid flow therethrough on release of connection of saidfirst valve second outlet and said sample receiver upper cut-off valve.7. A liquid metering apparatus comprising, in operative combination a. arigid walled chamber extending upwardly, an upper outlet in said chamberat the upper end thereof, a lower orifice in said second chamber at thebottom thereof, differential valve means in said upper outlet having apassage for passing gas freely therethrough but preventing free passageof water therethrough and movable to seal passage of liquid therepast;b. a valve with one inlet connected to a coupling through a constantvolume conduit and an orifice therebetween and a second inlet connectedto the lower orifice in said chamber which orifice is located above saidvalve spool means in said valve, spool holding means in said valveholding said spool means in a first position whereat the second inletthereof is connected to a second outlet and said second outlet isconnected to the atmosphere and said second inlet and said one inlet aredisconnected from each other, and c. wherein said differential valvecomprises a valve chamber with a lower inlet and an upper outlet and avertical side wall and a movable piston in said chamber, said pistonhaving a skirt slidably fitting the chamber walls and a perforated yokeabove said skirt and an imperforate plate above said yoke and attachedthereto, perforations in said yoke, a valve orifice in said chamberroof, said plate being larger than said orifice and in one, elevated,position thereof, in gas-tight sealing relation therewith, said plateedge being spaced a greater distance further from said chamber wall thansaid skirt and a lesser distance than the size of said perforations insaid yoke, whereby water forms a meniscus between the edge of said plateand said valve chamber wall and water flows freely through saidperforated yoke.
 8. A process of sampling a fluid stream over a periodof time while continouosly passing one portion of said fluid streamthrough a first conduit by periodically and discontinuously withdrawingsamples from aid fluid stream by a series of periodically repeated likecycles of steps, each such cycle of steps being completed in a separateperiodic time interval, each such periodic time interval spaced in timefrom another in said series of periodic time intervals and within saidperiod of time, each of said cycles comprising the steps of a.periodically diverting a second portion of such fluid stream to a secondconduit at a predetermined fixed pressure and then, for a first portionof each of said periodic time intervals, passing a first volume of saidsecond portion of said fluid stream through said second conduit for asufficient time to purge said second conduit of fluid therein, and b. i.passing a fixed portion of a volume of an incompressible metering liquidfrom a first chamber of fixed volume in contact with a first samplevolume of said second portion of said fluid stream initially at saidpredetermined pressure through a third conduit of fixed internaldiameter and length into bottom of a second upstanding chamber of fixedvolume and initially containing a second gas and discharging all thesaid second gas and a fixed amount of said metering liquid from saidsecond chamber and said third conduit, and thereby filling said thirdconduit and said second chamber with said incompressible metering liquidand thereby lowering the pressure in said first chamber to below saidpredetermined pressure, and, thereafter, b. ii. in a second portion ofsaid periodic time intervals which follows said first portion of saidperiodic time interval discharging from said second chamber and thirdconduit all of the fixed volume of said second fluid theretofore thereinpassing a second volume of said second portion of said fluid stream intosaid first chamber and raising the pressure therein to saidpredetermined pressure and thereby in each such cycle locating in saidfirst chamber one increment of fixed volume and pressure of said secondstream of fluid.
 9. Process as in claim 8 comprising the step ofremoving said first chamber from said second conduit and said thirdconduit at said predetermined pressure without loss of said incrementsof said second stream therefrom and operatively connecting to saidsecond and third conduits another chamber of fixed volume filled with asecond volume of said incompressible metering liquid.
 10. Process as inclaim 8 wherein said purging of said second conduit occurs while thepressure in said first chamber is being reduced by withdrawal of saidmetering liquid from the first chamber.
 11. A process as in claim 9wherein said fluid is a gas and said gas is substantially insoluble insaid incompressible liquid and said first stream is free of pressuredrop in the zone whereat said second portion of said fluid stream isdiverted to said second conduit.
 12. A process as in claim 11 whereinsaid gas is a hydrocarbon gas source and said incompressible liquid iswater.
 13. Process as in claim 12 wherein all of the steps are performedautomatically at predetermined intervals.
 14. Process as in claim 13wherein said steps are initiated by remote control.
 15. A process forrepetitive periodic sampling of a first fluid comprising seriallyrepeated steps of a. passing a portion of said first fluid from a sourcethereof through a conduit line leading to a first chamber having a fixedvolume for a sufficient time to purge said conduit line of any fluidtheretofore therein, then passing another portion of said first fluidinto said first chamber, said first chamber containing a secondincompressible metering liquid at a predetermined initial pressure; andb. opening a valve passage from said first chamber of fixed volume andpassing such metering liquid through a first conduit of fixed internaldiameter and length into a second upstanding chamber of fixed volumeinitially filled with a second fluid; and c. reducing the pressure insaid first chamber and passing an additional sample of said first fluidfrom its source at said predetermined initial pressure into said firstchamber and passing a fixed volume of said second incompressiblemetering liquid from said first chamber through said valve and firstconduit and into said second chamber and thereby filling said conduitand said second cHamber with said second incompressible liquid, saidfirst fluid and said second fluid being substantially insoluble in saidincompressible metering liquid; and d. raising the first chamberpressure to said predetermined pressure and thereby locating in saidfirst chamber one increment of fixed volume and pressure of said firstfluid; and e. selectively discharging from said second chamber and firstconduit all of the fixed volume of said second fluid theretofore thereinto a holder therefor.
 16. Process as in claim 15 wherein said purging ofsaid second conduit occurs while the pressure in said first chamber isbeing reduced by withdrawal of said metering liquid from the firstchamber.
 17. Process as in claim 16 comprising the step of removing saidfirst chamber from said source conduit and said second conduit at saidpredetermined pressure without loss of said increments of said secondstream therefrom and operatively connecting to said source and secondconduits another chamber of fixed volume filled with a second volume ofsaid incompressible metering liquid.
 18. A process as in claim 19wherein said first fluid is a hydrocarbon liquid and said incompressibleliquid is an aqueous liquid.
 19. Process as in claim 19 wherein firstfluid gas is a hydrocarbon gas and said incompressible liquid is water.